Disturbed at Night

I'm very new to the Apple Watch & know very little -- also I'm old & not very technically savvy. So here's my question:

Last night my watch woke me up at 4:30 a.m. with a ding reminding me to get up & move!

I know I could fix this by putting Do Not Disturb on it all night but I don't want to block phone calls at night, just everything else. IOW, I don't want notifications or beeps or anything like that during my night-time hours, but I do want phone calls. Is there a way I can do this?

Thanks.